The present invention relates generally to rotary fluid transfer devices such as pumps and internal combustion engines, and particularly rotary internal combustion engines. The invention also relates to methods for generating mechanical work from chemical potential energy using such engines.
Internal combustion engines have been conceived of in a variety of designs. A well-known and commonly used internal combustion engine design is a reciprocating piston engine. Reciprocating piston engines, however, have several disadvantages. Reciprocating piston engines tend to be large and heavy, and are of complex construction. Reciprocating piston engines typically comprise a large number of moving parts. Accordingly, reciprocating piston engines typically experience relatively rapid wear and have relatively low rates of utilization of the potential energy in the fuel consumed by such engines. The large weight of reciprocating piston engines typically results in a low power-to-weight ratio. In addition, reciprocating piston engines commonly employ designs, which introduce opposing forces on the drive mechanism during engine operation, decreasing net power and efficiency of the engine, and promoting wear on the drive mechanism.
Another known internal combustion engine design is the rotary engine. The rotary engine was originally devised to provide a simplified means for converting energy in fuel into rotary motion as compared to conventional reciprocating piston engines. In addition, the rotary engine was intended to provide a more efficient engine with fewer moving parts. Such an engine would, in theory, be less susceptible to wear than conventional reciprocating piston engines as a result of the reduction in the number of moving parts. Rotary engines have also been developed in an attempt to obtain increased power-to-weight ratios over those of conventional reciprocating piston engines.
Rotary engines to date have been met with limited success, however, because drawbacks in known rotary engine designs have prevented rotary engines from replacing conventional reciprocating piston engines as a preferred engine design. In some rotary engine designs, the relative speed between adjacent moving and stationary parts is such that effective sealing between such moving and stationary parts during engine operation is not reliably achieved over extended periods of use. Such ineffective sealing may result in decreased engine performance and/or efficiency. For example, some rotary engines utilize stationary chambers that are periodically sealed by a rotating rotor. Because the rotor is often rotating at high speed with respect to the stationary chambers during engine operation, effective sealing by the rotor of gases or fluids in the chambers is not reliably accomplished. Such ineffective sealing of the chambers may allow gases or fluids within the chambers to escape thus reducing engine efficiency and/or performance.
Some rotary engines incorporate protuberances extending from an inner rotating rotor which protuberances remain in contact with a stationary outer housing substantially throughout the rotor revolution to thereby define distinct closed chambers between the rotor and the outer housing for gas or fluid compression and expansion. Rotor rotation typically causes the protuberances to move with respect to the outer housing while the protuberances are in intimate contact with the outer housing. The movement of the protuberances with respect to the outer housing causes frictional energy losses in the engine, thus reducing engine efficiency and performance. In addition, respective protuberances may not form continuous seals with the outer housing throughout the entire rotor revolution, thus breaching respective closed chambers between respective protuberances and the outer housing. Such breaches of the closed chambers may allow gases within the breached chambers to escape, thus reducing the amount of working gases within the combustion chamber, and thereby reducing engine efficiency and performance.
A further problem that exists in known rotary engines is dynamic imbalances introduced to the engine through eccentric rotation of the rotor. Such dynamic imbalances can cause excessive wear on engine parts.
The rotary internal combustion engines proposed to date have failed to sufficiently overcome the problems discussed above.
It is therefore desired to have internal combustion engines which address certain limitations of known rotary and reciprocating piston engines. In addition, it is desired to have internal combustion engines which exploit the inherent rotary engine advantages over conventional reciprocating piston engines.
Specifically, it is an object of the invention to provide engines and pumps having increased efficiency over conventional reciprocating piston engines and pumps.
It is a further object of the invention to provide engines having increased power-to-weight ratios over conventional rotary and reciprocating piston engines.
It is yet another object of the invention to provide engines and pumps which effectively trap and seal gases within one or more chambers.
A further object of the invention is to provide engines and pumps which maintain dynamic internal balances.
It is another object of the invention to provide engines and pumps having significantly reduced frictional losses as compared to known rotary engines.
The invention is generally directed toward a rotary device for receiving fluid input and generating a fluid discharge therefrom. The rotary device comprises a stationary outer housing, a rotatable cylinder housing, and a rotatable wheel. The stationary outer housing has a circumferential outer wall comprising a first outer surface and a second opposing annular inner surface. The cylinder housing is positioned within the outer housing, and comprises a generally annular outer surface disposed toward and positioned in generally close juxtaposition with at least a portion of the second inner surface of the outer housing. The cylinder housing further includes a central opening therein and a plurality of open cylinders defining passages extending from the central opening generally to the outer surface of the cylinder housing. The cylinder housing further defines a central housing axis of rotation. The rotatable wheel is positioned within the central opening, and defines a wheel axis of rotation displaced from the cylinder housing axis of rotation. At least one inlet aperture receives fluid input into the rotary device and thus into the at least one open cylinder. At least one discharge aperture discharges fluid from the rotary device. A plurality of pistons are connected to the wheel, and extend into respective ones of the open cylinders thereby to define closed fluid processing chambers between the pistons and the inner surface of the outer housing. The rotatable wheel, the pistons, and the rotatable cylinder housing are cooperatively designed and configured to rotate substantially in unison within the stationary outer housing whereby the pistons move in reciprocating paths along longitudinal axes of the cylinders such that sizes of spaces within the cylinders between top sides of the pistons and the tops of the fluid processing chambers alternately increases and decreases, thereby defining variable angles xcex2 of about 10 degrees to about 30 degrees, at heads of the pistons between the longitudinal axis of the respective cylinder and a radian extending from the wheel axis of rotation to the head of the respective piston.
In preferred embodiments, the outer housing includes at least one aperture sized and configured to receive an igniter, the aperture being positioned proximate a compression locus of the rotary device.
In preferred embodiments, the rotary device includes at least one igniter disposed in the respective igniter aperture.
In some embodiments, the outer housing includes at least one aperture for intake of fresh air, at least one aperture for intake of fuel, and at least one aperture for exhaust of an ignited fuel/air mixture.
A ring gasket can be disposed at the outer surface of the cylinder housing, optionally surrounding an opening in the outer surface of the cylinder housing, wherein the opening is defined by a respective cylinder. Such ring gasket may be in intimate contact with both the outer surface of the cylinder housing and the inner surface of the outer housing.
In some embodiments, the rotatable wheel includes a central wheel body and at least one radial arm extending outwardly from the central wheel body, the radial arm having a first edge surface extending in a plane parallel to a tangent to the wheel body.
Preferably, the first edge surface includes a slide fixture extending along the length thereof, with the slide fixture being secured to the rotatable wheel at the first edge surface.
Preferably, the rotatable wheel is substantially disc-shaped, the wheel including a first end, a second opposing end, and a third circumferential side there between, the at least one radial arm being defined in the third side, a wheel shaft extending outwardly from the first end, a longitudinal axis of the wheel shaft coinciding with the wheel axis of rotation.
In preferred embodiments, the housing axis of rotation is displaced from the wheel axis of rotation. Typically, the magnitude of displacement between the wheel axis and the housing axis determines the compression ratios in the respective cylinders.
Also in preferred embodiments, respective pistons are connected to respective piston rods, the pistons, the piston rods, and the first edge surfaces, in combination, being configured such that a force applied by a fluid on a top of a respective piston is directed at the first edge surface of the corresponding radial arm at an angle of at least 75 degrees, preferably at least 80 degrees, more preferably at least 85 degrees, and is most preferably perpendicular, with respect to the first edge surface.
The rotary device is in general configured such that an expansive force, associated with a fluid being compressed in a respective fluid processing chamber while the respective piston is in a compression phase of rotation of the cylinder housing, urges the wheel in the same rotational direction as an expansive force associated with an expanding gas trapped within the fluid processing chamber while the respective piston is in an expansion phase of rotation of the cylinder housing.
In some embodiments the rotary device includes a cylinder head in a respective cylinder proximate the outer surface of the cylinder housing. The cylinder head comprises a solid structure having first topside and a second generally opposing bottom side, the first topside being disposed toward the inner surface of the outer housing. The cylinder head preferably includes at least one aperture forming an open passage from the top side to the bottom side, and preferably occupies a cross-sectional area of the chamber.
The invention further comprehends a rotary device wherein the rotary wheel has a wheel axis of rotation defined therein, a central body portion, and a plurality of radial arms extending outwardly from the central body portion, and a plurality of pistons slidably secured to respective ones of the radial arms, and received in respective ones of the cylinders, thereby to define closed fluid processing chambers between the pistons and the inner surface of the outer housing, whereby the pistons move in reciprocating paths along longitudinal axes of the cylinders, the rotatable wheel, the pistons, and the rotatable cylinder housing being cooperatively designed and configured to rotate substantially in unison within the stationary outer housing whereby the pistons move in reciprocating paths along longitudinal axes of the cylinders.
Preferably, the outer housing includes at least one aperture for intake of fresh air into the fluid processing chambers, at least one aperture for intake of fuel into the fluid processing chambers, and at least one aperture for exhaust of ignited fuel/air mixtures from the fluid processing chambers.
Some embodiments include a cylinder head in a respective cylinder, and a ring gasket extending about a perimeter of the cylinder at a top of the cylinder, and interfacing with the inner surface of the outer housing.
The invention yet further comprehends a rotary device for receiving fluid input, and generating a fluid discharge therefrom, wherein the rotatable wheel is positioned within the central opening, the rotatable wheel having a central wheel body and a plurality of radial arms extending outwardly from the central wheel body, and a plurality of pistons connected to respective radial arms for sliding engagement with the radial arms wherein the direction of sliding of a such sliding engagement is represented in a plane parallel to a tangent to the wheel body, and wherein the rotatable cylinder housing, the rotatable wheel, and the pistons rotate in a common rotation about a common central axis within the stationary outer housing thereby to define closed fluid processing chambers between the pistons and the inner surface of the outer housing.
The invention still further contemplates a rotary internal combustion engine, comprising a stationary outer housing having a circumferential outer wall comprising a first outer surface and a second opposing annular inner surface; a rotatable cylinder housing positioned within the outer housing, the cylinder housing comprising a generally annular outer surface disposed toward and positioned in generally close juxtaposition with at least a portion of the second inner surface of the outer housing, the cylinder housing including a central opening therein and a plurality of open cylinders defining passages extending from the central opening generally to the outer surface of the cylinder housing; a rotatable wheel positioned within the central opening; a plurality of pistons connected to the rotatable wheel and extending into respective ones of the open cylinders thereby to define closed combustion chambers between the pistons and the inner surface of the outer housing; a cylinder head in the cylinder housing associated with each the cylinder at or adjacent the outer surface of the cylinder housing, each respective cylinder head comprising solid structure disposed between the inner surface of the outer housing and a portion of the top of the respective piston; a ring gasket disposed at the outer surface of the cylinder housing; and at least one gas passage associated with each cylinder effective to provide sufficient freedom and distribution of fluid flow through the at least one passage from the respective underlying combustion chambers to locations proximate the inner surface of the outer housing at the respective cylinders such that the power generated in the combustion chambers is generally unaffected by fluid flow through the at least one gas passage.
In preferred embodiments, the rotatable inner housing, the wheel, the piston, and the porous head rotate substantially in unison within the stationary outer housing whereby the pistons move in reciprocating paths along longitudinal axes of the cylinders such that spaces within the cylinders between top ends of the pistons and the tops of the combustion chambers alternately increase and decrease.
In some embodiments, the wheel includes a central body and a plurality of radial arms extending outwardly from the wheel body, the radial arms comprising first edge surfaces extending in planes parallel to tangents to the wheel body.
In some embodiments, the first edge surface includes a slide fixture extending along the length of the respective first edge surface, the slide fixtures being secured to the respective first edge surfaces.
In preferred embodiments, the wheel is substantially disc-shaped, and defines a wheel axis of rotation, the wheel including a first end, a second opposing end, and a third circumferential side therebetween, the at least one radial arm being defined in the third side, a first shaft extending outwardly from the first end, a longitudinal axis of the first shaft coinciding with the wheel axis of rotation.
In preferred embodiments, the cylinder housing defines a housing axis of rotation, displaced from the wheel axis of rotation, and wherein the magnitude of the displacement between the wheel axis and the housing axis determines the compression ratios in the respective cylinders.
In preferred embodiments, the pistons are connected to respective piston rods, and the piston rods are connected to the first edge surface of the radial arm, and the pistons, the piston rods, and the first edge surface are, in combination, configured such that a force applied by combusting fuel on a top of a respective such piston in the combustion chamber, is directed at the first edge surface of the corresponding radial arm at an angle of at least 75 degrees, preferably a perpendicular angle, with respect to the first edge surface.
In preferred embodiments, the rotary device is configured such that an expansive force, associated with intake gases being compressed in a respective combustion chamber while the respective piston is in a compression phase of rotation of the cylinder housing, urges the wheel in the same rotational direction as an expansive force associated with expanding gases of combustion trapped within the combustion chamber while the piston is in an expansion phase of rotation of the cylinder housing.
In some embodiments, the ring gasket substantially surrounds an opening in the outer surface of the cylinder housing and the opening is defined at least in part by a respective cylinder.
The invention also comprehends a method of converting chemical potential energy in a fuel into rotational motion in a rotary device including a stationary outer housing having a circumferential outer wall comprising a first outer surface and a second opposing annular inner surface. The stationary housing includes at least one aperture extending through the outer wall to thereby provide a passage from the first outer surface to the second inner surface. The rotary device further includes a rotatable cylinder housing comprising an outer surface disposed toward the second inner surface of the outer housing, the cylinder housing including a central opening and a plurality of open cylinders defining passages from the central opening to the outer surface of the cylinder housing, the rotatable cylinder housing defining a housing axis of rotation. The rotary device still further includes a rotatable wheel positioned within the central opening, the rotatable wheel defining a wheel axis of rotation of the rotatable wheel, displaced from the housing axis of rotation, and a plurality of pistons connected to the rotatable wheel and extending into respective ones of the open cylinders thereby to define closed combustion chambers between the pistons and the inner surface of the outer housing. The method comprises providing at least initial rotational motion to the cylinder housing, whereby the rotatable wheel and the pistons rotate in unison with the cylinder housing; providing combustion air and fuel to a respective combustion chamber so as to provide a fuel-air mixture therein; igniting the fuel/air mixture in the combustion chamber; enabling the ignited fuel/air mixture to expand within the combustion chamber by enabling the wheel to rotate, whereby the displacement of the wheel axis and the housing axis from each other causes the piston to move longitudinally in the respective combustion chamber, away from the inner surface of the outer housing; and exhausting the combustion gases from the combustion chamber.